The metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more cl...The metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more closely related to acid rocks. The abundance of Cu is relatively high in the intermediate-acid rocks and subvolcanic rocks, whereas the abundances of Pb, An and Ag are high in acid rocks, indicating rich ore-forming elements in original magmas. The study of REEs shows that the magmatic type related to copper deposits is the syntectic type, and that related to silver polymetallic deposits is mainly the re-melting type. The deposits were formed under medium-low temperatures and low salinity. The metallogenic times were the late stage of the early Yanshanian or the late Yanshanian, dating 78–147 Ma.展开更多
In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in lran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consi...In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in lran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consisted ofCu, Ag, Pb and Se. Amount of Ag in the considered anode slime was 5.4% （by weight）. The goal was to recover as much as possible Ag from anode slime at atmospheric pressure to synthesize Ag nanoparticles. Therefore, acid leaching was used for this purpose. The anode slime was leached with sulfuric and nitric acid from room to 90 ~C at different acid concentrations and the run which yielded the most recovery of Ag was selected for Ag nanoparticles synthesis. At this condition, Cu, Pb and Se are lea- ched as well as Ag. To separate Ag from leach solution HCI was added and silver was precipitated as AgCl which were then dissolved by ammonia solution. The Ag nanoparticles are synthesized from this solution by chemical reduction method by aid of sodium borohydride in the presence of PVP and PEG as stabilizers. The synthesized Ag nanoparticles showed a peak of 394 nm in UV-vis spectrum and TEM images showed a rather uniform Ag nanoparticles of 12 nm.展开更多
In the present work, an easy solid phase extraction method using alumina modified with polyethylenimine as a new adsorbent was applied to the simultaneous extraction of copper, silver, and palladium ions prior to thei...In the present work, an easy solid phase extraction method using alumina modified with polyethylenimine as a new adsorbent was applied to the simultaneous extraction of copper, silver, and palladium ions prior to their determination with electrothermal atomic absorption spectrometry. The analytical procedure involved the complex formation of these cations with polyethylenimine as a chelating agent in buffer media of pH 7.0. Under the optimum conditions, a preconcentration factor of 200, 150, and 200, precision of ~5.4%, ＋4.7%, and ＋5.2% and linear calibration ranges of 15.0-140, 4.0-93, and 7.5-125 ng/L （in original solution） for Cu, Ag, and Pd were obtained, respectively. Also detection limits of 3.9,1.1, and 2.0 ng/L were obtained for Cu, Ag, and Pd, respectively. The proposed method was applied to the determination of copper, silver, and palladium in some real samples with satisfactory results.展开更多
Titanium dioxide （TiO2） is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO2...Titanium dioxide （TiO2） is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO2 nanowire membrane （Cu-Ag-TiO2） was prepared and evaluated for its efficiency to inactivate E. coli and bacteriophage MS2. Enhanced photo-activated bactericidal and virucidal activities were obtained by the Cu-Ag-TiO2 membrane than by the TiO2, Ag-TiO2 and Cu-TiO2 membranes under both dark and UV light illumination. The better performance was attributed to the synergies of enhanced membrane photoacfivity by loading silver and copper on the membrane and the synergistic effect between the free silver and copper ions in water. At the end of a 30 min test of dead- end filtration under 254 nm UV irradiation, the Cu-Ag-TiO2 membrane was able to obtain an E. coli removal of 7.68 log and bacteriophage Ms2 removal of 4.02 log, which have met the US EPA standard. The free metal ions coming offthe membrane have concentrations of less than 10 ppb in the water effluent, far below the US EPA maximum contaminant level for silver and copper ions in drinking water. Therefore, the photo-activated disinfection by the Cu-Ag-Ti02 membrane is a viable technique for meeting drinking water treatment standards of microbiological water purifiers.展开更多
Silver nanoplates as novel optical sensors for Cu^2＋ detection have been demonstrated.Silver nanoplates are synthesized via previous H_2O_2-NaBH_4 cyclic oxidation-reduction reactions.With introduction of ascorbate a...Silver nanoplates as novel optical sensors for Cu^2＋ detection have been demonstrated.Silver nanoplates are synthesized via previous H_2O_2-NaBH_4 cyclic oxidation-reduction reactions.With introduction of ascorbate as mild reductants,Cu^2＋ ions are reduced into Cu~＋ and the Cu^＋ is further reduced to Cu,which is deposited on the surface of the silver nanoplates.The deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon absorption.Therefore,trace Cu^2＋ can be detected.The shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu^2＋concentration over a range of 40-340 μmol L^（-1） with a limit of detection of 9.0 μmol L^（-1）.Moreover,such silver nanoplate-based optical sensors provide good selectivity for Cu^2＋ detection,and most other metal ions do not disturb its detection.Moreover,the practicality of the proposed sensor was tested.This Cu^2＋assay is advantageous in its simplicity,selectivity,and cost-effectiveness.展开更多
文摘The metallogenesis of subvolcanic deposits is controlled by subvolcanic activities. The copper polymetallic deposits are genetically related to intermediate-acid rocks, and the silver polymetallic deposits are more closely related to acid rocks. The abundance of Cu is relatively high in the intermediate-acid rocks and subvolcanic rocks, whereas the abundances of Pb, An and Ag are high in acid rocks, indicating rich ore-forming elements in original magmas. The study of REEs shows that the magmatic type related to copper deposits is the syntectic type, and that related to silver polymetallic deposits is mainly the re-melting type. The deposits were formed under medium-low temperatures and low salinity. The metallogenic times were the late stage of the early Yanshanian or the late Yanshanian, dating 78–147 Ma.
基金the International Center for Science, High Technology & Environmental Sciences for financial support of this work (No. 1.213)
文摘In this paper, recovery of silver from anode slime of Sarcheshmeh copper complex in lran and subsequent synthesis of silver nanoparticles from leaching solution is investigated. Sarcheshmeh anode slime is mainly consisted ofCu, Ag, Pb and Se. Amount of Ag in the considered anode slime was 5.4% （by weight）. The goal was to recover as much as possible Ag from anode slime at atmospheric pressure to synthesize Ag nanoparticles. Therefore, acid leaching was used for this purpose. The anode slime was leached with sulfuric and nitric acid from room to 90 ~C at different acid concentrations and the run which yielded the most recovery of Ag was selected for Ag nanoparticles synthesis. At this condition, Cu, Pb and Se are lea- ched as well as Ag. To separate Ag from leach solution HCI was added and silver was precipitated as AgCl which were then dissolved by ammonia solution. The Ag nanoparticles are synthesized from this solution by chemical reduction method by aid of sodium borohydride in the presence of PVP and PEG as stabilizers. The synthesized Ag nanoparticles showed a peak of 394 nm in UV-vis spectrum and TEM images showed a rather uniform Ag nanoparticles of 12 nm.
文摘In the present work, an easy solid phase extraction method using alumina modified with polyethylenimine as a new adsorbent was applied to the simultaneous extraction of copper, silver, and palladium ions prior to their determination with electrothermal atomic absorption spectrometry. The analytical procedure involved the complex formation of these cations with polyethylenimine as a chelating agent in buffer media of pH 7.0. Under the optimum conditions, a preconcentration factor of 200, 150, and 200, precision of ~5.4%, ＋4.7%, and ＋5.2% and linear calibration ranges of 15.0-140, 4.0-93, and 7.5-125 ng/L （in original solution） for Cu, Ag, and Pd were obtained, respectively. Also detection limits of 3.9,1.1, and 2.0 ng/L were obtained for Cu, Ag, and Pd, respectively. The proposed method was applied to the determination of copper, silver, and palladium in some real samples with satisfactory results.
文摘Titanium dioxide （TiO2） is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO2 nanowire membrane （Cu-Ag-TiO2） was prepared and evaluated for its efficiency to inactivate E. coli and bacteriophage MS2. Enhanced photo-activated bactericidal and virucidal activities were obtained by the Cu-Ag-TiO2 membrane than by the TiO2, Ag-TiO2 and Cu-TiO2 membranes under both dark and UV light illumination. The better performance was attributed to the synergies of enhanced membrane photoacfivity by loading silver and copper on the membrane and the synergistic effect between the free silver and copper ions in water. At the end of a 30 min test of dead- end filtration under 254 nm UV irradiation, the Cu-Ag-TiO2 membrane was able to obtain an E. coli removal of 7.68 log and bacteriophage Ms2 removal of 4.02 log, which have met the US EPA standard. The free metal ions coming offthe membrane have concentrations of less than 10 ppb in the water effluent, far below the US EPA maximum contaminant level for silver and copper ions in drinking water. Therefore, the photo-activated disinfection by the Cu-Ag-Ti02 membrane is a viable technique for meeting drinking water treatment standards of microbiological water purifiers.
基金supported by the National Natural Science Foundation of China(No.21375036)the Open Project Program of Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education(Hunan University of Science and Technology,No.E21201)
文摘Silver nanoplates as novel optical sensors for Cu^2＋ detection have been demonstrated.Silver nanoplates are synthesized via previous H_2O_2-NaBH_4 cyclic oxidation-reduction reactions.With introduction of ascorbate as mild reductants,Cu^2＋ ions are reduced into Cu~＋ and the Cu^＋ is further reduced to Cu,which is deposited on the surface of the silver nanoplates.The deposition of the Cu on the surface of the silver nanoplates allows a significant red-shift of their plasmon absorption.Therefore,trace Cu^2＋ can be detected.The shift of the plasmon absorption wavelength of silver nanoplates is proportional to the Cu^2＋concentration over a range of 40-340 μmol L^（-1） with a limit of detection of 9.0 μmol L^（-1）.Moreover,such silver nanoplate-based optical sensors provide good selectivity for Cu^2＋ detection,and most other metal ions do not disturb its detection.Moreover,the practicality of the proposed sensor was tested.This Cu^2＋assay is advantageous in its simplicity,selectivity,and cost-effectiveness.
